H2—O2(air) fuel cells are well known in the art and have been proposed as a power source for many applications both mobile and stationary. There are several types of H2—O2 fuel cells including acid-type, alkaline-type, molten-carbonate-type, and solid-oxide-type. A plurality of individual cells are commonly bundled together to form a fuel cell stack. In these fuel cells hydrogen is the anode reactant (i.e., fuel) and oxygen is the cathode reactant (i.e., oxidant). The oxygen can either be in a pure form (i.e., O2), or air (i.e., O2 mixed with N2). During the conversion of the anode reactant and cathode reactant to electrical energy, the fuel cell, regardless of the type, produces anode and cathode effluents that are exhausted from the fuel cell stack.
The fuel cell stack is typically part of a fuel cell system. The fuel cell system may include such things as a hydrogen storage device and hardware (i.e., injectors, piping, valves, sensors, etc.) associated with supplying the hydrogen to the fuel cell stack, a compressor or similar device and associated hardware for supplying the oxygen to the fuel cell stack, a coolant system and associated hardware to supply a coolant stream to the fuel cell stack, various sensors and meters, and a microprocessor or similar device operable to monitor and control the operation of the fuel cell stack and system. The fuel cell stack receives various fluid streams (i.e., a hydrogen-containing stream, an oxygen-containing stream and a coolant stream) that flow through a multitude of piping, sensors, valves and the like prior to and/or after flowing through the fuel cell stack. These various fluid steams may be separated by various membranes, gaskets and similar components. The close proximity of the fluid steams to one another and the multitude of hardware through which each stream flows represent potential sources from which hydrogen migrates and cross-contamination (i.e., an undesired mixing of two of more streams).
Such migration and cross-contamination are undesirable. To prevent migrating hydrogen from escaping the fuel cell system unimpeded, it is desirable to locate various components of the fuel cell system within an enclosure that functions to contain and direct the leaked hydrogen to a desired location or component. It is also desirable to be able to detect the presence of hydrogen in the enclosure so that a corrective action can be commenced.